Joan, Pope, a woman who, in the guise of a man with male accomplishments, is said for two years five months and four days to have been Pope of Rome between Leo IV. and Benedict III. about 853-855, and whose sex was discovered by the premature birth of a child during some public procession. She is said to have been of English parentage, and to have borne the name of Gilberte. However, it is but fair to say that the story is of doubtful authenticity.
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Joachim, St. * Joan of Arc